Hacking bar codes for your LEGO® set

Building with LEGO® blocks is a fun way to capture young imaginations. Modern LEGO sets have become very elaborate, like the new Nexo Knights. These sets come with Nexo Powers, which are little shields that have a small picture on them, representing a special power that can be uploaded to an app by taking a picture of it.

What you may not notice is that these little shields are actually cleverly designed bar codes. One way to collect these powers would be to buy up all the LEGO sets and snap pictures of every shield. But that’s no fun! If you want to add a bit of a challenge to quest, you can forge your own by hacking the system. By rearranging these bar codes, you can figure out how to make your own.

Take, for example, the Nexo Blade power (#402). This power is the easiest to find because it is printed on the cover of just about every Nexo Knight publication. Next to it is a stripped-down version that has nothing but the little squares around the inside edge. Next to that, is another stripped-down version where the code has been inverted. All three of these images scan successfully and “unlock” the power in the Nexo Knight app.

The folks at LEGO are smart enough to know that people will be tempted to snap pictures without actually buying merchandise. So they invented a “combo power” that can only be unlocked by scanning three powers at once, which is next to impossible if you’re taking a picture here and another one there. But if we recreate the bar code patterns on paper with an ordinary felt-tipped marker, we can take a snapshot of three shields at once.

The bar code consists of twelve boxes to the left, ten boxes along the top, and twelve on the right, for a total of 32 boxes. These boxes are either shown as opaque or empty. Translated into computer speak, that is 32 bits of binary data, which theoretically could represent over 4 billion kinds of Nexo Powers. Luckily there are only about 470.

A kid-friendly activity we’ve done at home: print blank Nexo Powers, hand them out to a group, and let them color in boxes. With at least one Nexo Knight-enabled device, see who can find the most powers. Often, patterns that are symmetrical, or patterns that look visually pleasing, are more likely to have a power.

Have you found any unpublished powers? Any interesting combos? Let us know in the comments.